The present invention relates to a compensating element for a fuel injector.
A fuel injection system having a compensating element is known from German Published Patent Application No. 197 35 665, the compensating element including a supporting body, which has a dome-shaped supporting surface. A fuel injector is supported by this compensating element in a receiving bore of a cylinder head. Since the fuel injector rests on the spherically shaped surface by the supporting surface, the fuel injector is able to be mounted at an angle that deviates from the axis of the receiving bore by up to a certain amount, and can be pressed firmly into the receiving bore by appropriate means, e.g., a clamping shoe. This allows a simple adaptation to the fuel supply lines. Tolerances arising in the manufacture and in the mounting of the fuel injectors can be compensated for.
It is disadvantageous, however, that the supporting body requires expensive manufacturing and that a precisely manufactured, spherical surface is needed. The rigid supporting body cannot be compressed, and thus no compensation in the axial direction of the receiving bore occurs. Moreover, tolerance can only be compensated with respect to the specified geometry of the spherical surface. A radial compensation movement purely with respect to the receiving bore is not possible.
In contrast, the compensating element for a fuel injector according to the present invention has the advantage that the fuel injector is supported by a washer having an oval or round cross-section, which is inserted between the fuel injector and a wall of a receiving bore of the cylinder head accommodating the fuel injector, and which has no sealing function. Due to its elasticity, the compensating element compensates for manufacturing tolerances of the individual components as well as for tolerances that are caused by the warming of the fuel injector during operation, and in this manner prevents twisting and malpositions.
It is especially advantageous that the washer may either be slit and then pressed onto a valve housing of the fuel injector by press-fitting, or be designed in the form of a closed ring which may be loosely slipped onto the valve housing.
Advantageously, the washer may be fabricated out of wire, made of alloyed or non-alloyed steel, for example.
In this context, a manufacture using copper or a copper alloy is particularly advantageous since copper has high thermal conductivity and excellent surface adaptation.